JP2003111668A - Container for induction heat-cooking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a container for an induction heat-cooking wherein the overheating of a heater is avoided by increasing the radiation efficiency when heat-cooking, and damages of the container can be suppressed. SOLUTION: This container for the induction heat-cooking is equipped with the cylindrical container having a bottom comprising a non-conductive material. Heat is generated by an electromagnetic induction. The upper surface of the heater has an unevenness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating cooking container capable of heating contents by an induction heating cooker utilizing induction heating.

[0002]

2. Description of the Related Art A container for induction heating and cooking of this kind is provided with a heating element that generates heat by electromagnetic induction. When the container is placed on an induction heating cooker and an electric current is passed through an induction heating coil of the cooker, A high frequency magnetic field is generated to induce an eddy current in the heating element, and the heating element generates heat due to resistance loss due to the eddy current, thereby warming the contents.

[0003]

By the way, recently,
It has also been proposed that the container body is made of a non-conductive material such as plastic or paper, and a flat heating element is fixed to the outer surface or the inner surface of the bottom portion, or a heating element is built in the bottom portion. However, since the heating element is fixed and closely attached to the bottom of the container body, when the heating element continuously generates heat due to continuous energization, the bottom of the container body may be excessively heated.

Therefore, the present invention has been made in view of the above-mentioned problems of the prior art. By improving the heat dissipation efficiency of the heating element during cooking, excessive heating of the heating element is suppressed and damage to the container body due to heat is suppressed. An object of the present invention is to provide a container for induction heating that can be used.

[0005]

The present invention has been made to solve the above problems, and an induction heating cooking container according to the present invention comprises a bottomed cylindrical container body made of a non-conductive material. In an induction heating cooking container provided with a heating element that generates heat by electromagnetic induction, the heating element is provided in the container body, and unevenness is provided on the upper surface of the heating element.

Further, it is preferable that a space is provided between the heating element and the bottom of the container body. By providing the space, the contact area between the heating element and the bottom can be reduced, and the space can be used for heat insulation. The effect suppresses damage to the bottom.

Further, it is preferable that the liquid such as water contained in the container body can enter the space,
Since the liquid circulates in the space, the heat dissipation efficiency of the heating element and the heating efficiency of the liquid are further improved. The liquid such as water may be contained in the container body in advance, or may be contained in the container body at the time of heating and cooking. In addition to water itself, liquids such as water include, for example, beverages such as coffee and juice, milk, soup, and the like.

The heating element is preferably placed on the inner surface of the bottom of the container body, and at least one of the inner surface of the bottom of the container body and the lower surface of the heating element is provided with a recess. In this case, since the heating element is placed, the contact area with the bottom is smaller than that of the bonded structure, and the recess forms a space between the heating element and the bottom of the container body. As a result, the contact area with the bottom can be greatly reduced, and therefore the thermal effect on the bottom is reduced. In addition, the heat insulating effect of the space also suppresses damage to the bottom due to heat. In addition, since the heating element is placed, the liquid such as water contained in the container body will infiltrate into the space during heating and cooking, and the liquid will circulate through the space to dissipate heat from the heating element. The efficiency and the heating efficiency of the liquid are further improved. In particular, since the concave portion is formed and the heating element is placed, the space portion can be easily formed between the heating element and the bottom of the container body.

Further, it is preferable that the heating element is placed on the inner surface of the bottom portion of the container body, and the heating element is formed with a through hole extending vertically therethrough. In this case, the through-holes form irregularities to increase the surface area, and since the heating element is placed, the contact area with the bottom is smaller than that of the bonded structure, and the heating A liquid such as water contained in the container body during cooking enters between the heating element and the bottom of the container body through the through hole. Therefore, since the liquid circulates through the through hole, the heating efficiency is improved, and the liquid such as water interposed between the bottom of the container body and the heating element further reduces the thermal effect on the bottom.

Further, it is preferable to use a magnetic metal material having a Curie temperature lower than the melting point of the container body plus 70 ° C. as the constituent material of the heating element.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of an induction heating cooking container according to the present invention will be described with reference to FIGS. 1 and 2, and a bottomed cylindrical container body 1 having an upper opening and heat generation by electromagnetic induction. An induction heating cooking container provided with the heating element 2, especially a structure suitable for a disposable simple plastic container will be described.

The container body 1 has a body portion 3 that expands upward in a substantially tapered shape, a substantially flat plate-like bottom portion 4 integrally formed with the body portion 3, and a body portion 3 of the body portion 3. The upper end portion is provided with a flange portion 5 formed over the entire circumference. The bottom inner surface 4a is a substantially flat surface. Vertical ribs 6 are formed radially on the outer peripheral surface of the body portion 3, and the flange portion 5 is formed in a substantially U shape in cross section. Further, the body 3 is formed such that the upper body 3a and the lower body 3b are continuous in a stepwise manner via a horizontal annular connecting portion 7, and an auxiliary piece 8 is provided at the lower end of the upper body 3a. It extends downward so as to have a predetermined gap with the body portion 3b.

A bottom portion 4 is provided on the inner peripheral surface of the lower body portion 3b.
An annular projection 9 is formed at a position above a predetermined height from the above to prevent the heating element 2 from moving upward. The protrusion 9 is a regulating means for regulating the upward movement of the heating element 2, and the heating element 2 is prevented from coming out of the container body 1 easily because the upper surface 2a of the heating element 2 comes into contact with the protrusion 9 and the upward movement is blocked. Absent. Note that the protrusion 9 does not have to be annular. In addition, the protrusion 9 serves as a regulation means.
However, when the projection 9 is provided, the heating element 2 may be pulled out from the container body 1 while the heating element 2 is forcibly pulled upward by hand to destroy the projection 9. It is possible and convenient for separate disposal.

The container body 1 having the above structure is formed of a thermoplastic resin by injection molding, and examples of the thermoplastic resin include polypropylene, high density polyethylene, polyethylene terephthalate, polycarbonate,
Examples include polyamide and polystyrene. In particular, polypropylene-based resins such as propylene-ethylene copolymer are preferable because they are light and have high mechanical strength, are inexpensive, have good moldability, and have high heat resistance temperature and heat distortion temperature and excellent heat resistance. However, the material of the container body 1 is not limited to these, and non-conductive materials such as paper can be used in addition to synthetic resin. Especially, if it is formed from synthetic resin or paper, it is light and can be incinerated and discarded. Since it is relatively easy, it is preferable as a disposable container. As described later, the effect of the present invention is great in the case of a non-heat resistant material such as synthetic resin or paper. Also, the torso 3
A cylindrical label may be attached to the outside of the.

The heating element 2 is housed in the container body 1 in a non-bonded state. The heating element 2 is made of a conductive material, for example, a metal material such as iron, stainless steel, chromium, aluminum or copper, or a non-metal material such as carbon. In particular, iron and stainless steel are preferable because they have high heat generation efficiency.
From the viewpoint of heat generation efficiency, a magnetic metal material (magnetic material), particularly a ferromagnetic metal material (ferromagnetic material) is generally preferable. The thickness of the heating element 2 is 0.05 to 1.0 mm, preferably 0.1 to 0.8 mm in the case of iron or stainless steel. The entire heating element 2 does not have to be a conductive material, as long as at least a part thereof is made of a conductive material.

In this embodiment, the heating element 2 is formed in a plate shape (disk shape) having a substantially flat lower surface 2b, and is placed on the bottom inner surface 4a of the container body 1 and the lower surface 2b is substantially flat. It contacts the bottom inner surface 4a of the surface. That is, the heating element 2 is placed on the bottom inner surface 4a of the container body 1 in a non-adhesive state, and a gap is formed between its peripheral surface and the inner peripheral surface of the container body 1.

The heating element 2 has irregularities on its upper surface 2a. Specifically, a plurality of convex portions 10 are formed on the upper surface 2a of the heating element 2 which is a portion that comes into contact with the contents to be cooked by being placed in the container body 1.
The surface area of the upper surface is increased by 0 as compared with the case of being flat. Various shapes can be adopted for the convex portion 10, and for example, the convex portion can be formed in a streak shape in addition to a hemispherical shape, a conical shape, a pyramidal shape, a cylindrical shape, a prismatic shape, a cylindrical shape, or the like. Alternatively, a plurality of streaky convex portions may be arranged in parallel to form a corrugated plate-shaped convex portion or the like.
The size of the convex portion 10 is, for example, in the case of a hemispherical shape, the diameter is about 0.5 to 3 mm, and the surface area of the upper surface 2a is 1.2 to 3 times as large as when the convex portion 10 is not provided and is flat. It is a degree.

When using the container having the above-mentioned structure for heating and cooking, a liquid, for example, water is put into the container body 1 at the time of heating and the container is placed on the cooking device to start heating and cooking. Although the heating element 2 generates heat, since the convex portion 10 is formed on the upper surface 2a of the heating element 2, the contact area between water and the heating element 2 is large, and therefore the water is efficiently heated by the heating element 2. . That is, by providing the convex portion 10 on the upper surface 2a, heat is efficiently generated on the flat lower surface 2b, and this heat is transmitted to the upper surface 2a having a large surface area, and the heat dissipation efficiency of the heating element 2 during heating and cooking is improved. The heating efficiency of the (contents) is improved, and the overheating of the heating element 2 is suppressed, so that damage to the container body 1, particularly the bottom portion 4 due to heat can be prevented. In addition, in the present embodiment, the heating element 2 is not fixed to the container body 1 but is placed on the bottom inner surface 4a, so that the heating element 2 is fixed to the bottom 4 as in the prior art or built-in. There is also an advantage that the contact area between the heating element 2 and the bottom portion 4 is smaller than that of the configuration, and therefore the heat effect from the heating element 2 is reduced as compared with the conventional case. Further, the water contained in the container body 1 slightly penetrates between the heating element 2 and the bottom inner surface 4a through the gap between the peripheral surface of the heating element 2 and the inner peripheral surface of the container body 1. Therefore, this water also suppresses the thermal effect on the bottom portion 4.

Further, by using a magnetic metal material having a Curie temperature below a predetermined temperature as a constituent material of the heating element 2, it is possible to suppress an excessive temperature rise of the heating element 2. That is, when the heat generating element 2 is made of a magnetic metal material having a predetermined Curie temperature, the temperature of the heat generating element 2 does not rise above the Curie temperature, and the temperature of the heat generating element 2 is maintained at the Curie temperature. 2 overheating is prevented. The Curie temperature of the heating element 2 is 80 to 330.
C is preferred.

On the other hand, the induction heating cooker generally employs a structure in which a switch is not turned on when the container does not generate heat by electromagnetic induction, or a structure in which the switch is automatically turned off. . Therefore, when an induction heating cooker to which such a safety device is not used is used, the Curie temperature of the magnetic metal material used for the heating element 2 is lower than the melting point of the resin forming the container body 1. Things are good. By using the heating element 2 having a Curie temperature lower than the melting point of the container body 1, the heating element 2 does not rise above the melting point of the container body 1 and is suitable for protecting the plastic container body 1. .

On the other hand, when the induction heating cooker adopting the above-mentioned safety structure is used, the heating element 2 is used.
It was found by the inventor's research that the magnetic metal material used for the above should have a Curie temperature lower than the melting point of the resin constituting the container body 1 plus 70 ° C. For example, when the container body 1 is polypropylene resin (PP),
Polyethylene terephthalate (PE having a Curie temperature of 110 ° C. or higher and its melting point less than 70 ° C.
In the case of polyesters such as T), those having a Curie temperature of 110 ° C. or more and their melting point plus less than 70 ° C. are preferable. Specifically, when the material of the container body 1 is polypropylene resin, the heating element 2 having a Curie temperature of 80 to 220 ° C.
To use. For example, when polypropylene resin having a melting point of 140 ° C. is used for the container body 1, the Curie temperature of the heating element 2 is preferably 110 ° C. or higher and lower than 210 ° C.
When polyester having a melting point of 260 ° C. is used for the container body 1, the Curie temperature of the heating element 2 is 110 ° C. or higher 33
The temperature is preferably lower than 0 ° C, and particularly preferably 120 to 290 ° C.
The polyester used for the container body 1 is preferably heat-resistant crystallized PET (so-called C-PET). When used in a cooker equipped with the above-mentioned safety device, if the heating element 2 is made of a magnetic metal material having a Curie temperature lower than the melting point of the container body 1 plus 70 ° C., the safety device operates to generate heat. When the heating of the body 2 is stopped, the temperature of the heating element 2 becomes lower than the melting point of the container body 1, and
Damage to the container body 1 due to heat was reliably prevented.

A ferromagnetic metal material is used as the magnetic metal material used for the heating element 2, and various alloys such as nickel alloys and iron-chromium alloys are used. And
Since the Curie temperature differs depending on the composition, the Curie temperature having a desired Curie temperature can be obtained by setting the composition. For example, the Curie temperature of nickel (Ni) is 358 ° C., but vanadium (V), chromium (Cr), silicon (S)
i), aluminum (Al), titanium (Ti), molybdenum (Mo), zinc (Zn), tin (Sn), copper (C)
When an element such as u) is added, the Curie temperature becomes low, and the Curie temperature also becomes low depending on the added amount of the added element. On the contrary, if iron (Fe) or cobalt (Co) is used as the additive element of the Ni alloy, the Curie temperature increases depending on the additive amount. For example, if the composition is 51 wt% Fe, 40 wt% Ni, and 9 wt% Cr, the Curie temperature is 135 ° C. In addition, Z in soft magnetic ferrite
The heating element 2 having a desired Curie temperature can also be obtained by selecting the addition amounts of oxides of n and Fe.

If it is better that the heating element 2 does not come into direct contact with the contents (food or the like), the heating element 2 is coated with a material (resin) having a heat resistance higher than the Curie temperature of the heating element 2. It can also be used.

As shown in FIG. 2, for example, a so-called instant food product in which a dried food W such as dried noodles is contained in the container body 1 and the top opening of the container body 1 is releasably sealed with a seal lid 20. It can also be used as a container. When eating the stored dry food W, the seal lid 20 is peeled halfway as shown by the chain double-dashed line, water is poured from the opening, and the seal lid 20 is placed on an induction heating cooker to generate heat from the heating element 2. To heat the water. Therefore, it is not necessary to prepare hot water in advance, and cooking is easy.

Further, in the configuration of FIG. 1, the lower surface 2 of the heating element 2 is
Although both b and the bottom inner surface 4a of the container body 1 were substantially flat, the heating element 2 can be formed by forming a recess in either one.
A space V may be formed between the bottom part 4 and the bottom part 4. For example,
In the case of the heat generating element 2 shown in FIG. 2, the concave portion 11 is formed in the lower surface 2b of the heat generating element 2 so that the space V is formed between the heat generating element 2 and the bottom inner surface 4a which is substantially flat. In particular, the heating element 2 is
The embossed thin plate has a convex portion 10 formed on the upper surface 2a and a concave portion 11 correspondingly formed on the lower surface 2b. By performing the embossing in this way, it is possible to form the concave portion 11 on the lower surface 2b in addition to the unevenness on the upper surface 2a at one time. The shape of the emboss is, for example, a corrugated plate having a large number of protrusions 10 such as hemispheres. In the case of hemisphere, the diameter is about 1 to 5 mm,
In the case of a corrugated plate, the width of the corrugation is about 1 to 5 mm.

By providing the space V in this way, the contact area between the heating element 2 and the container body 1 can be reduced, and at the same time, due to the heat insulating effect of the space V, the heating element 2 to the bottom portion 4 can be reduced. Heat transfer to the bottom part 4 is suppressed, and thus damage to the bottom portion 4 due to heat can be suppressed. Although it is possible to form the concave portion 12 in the bottom inner surface 4a of the container body 1 to form the space V as shown in FIG. 3, when the concave portion 11 is formed in the lower surface 2b of the heating element 2, the upper surface of the heating element 2 is formed. Not only the surface area of 2a but also the surface area of the lower surface 2b is increased, so that the heat dissipation efficiency of the heating element 2 is further enhanced.

Moreover, the container body 1 is similar to the above embodiment.
A gap is formed between the inner peripheral surface of the heating element 2 and the peripheral surface of the heating element 2, and the space V formed by the recess 11 and the contents-accommodating space above the heating element 2 communicate with each other. Therefore, during heating and cooking, the water contained in the container body 1 or the water (liquid) contained in the container body 1 in advance enters the space V from the periphery of the heating element 2 and circulates therein. By circulating the water in this way, the heat radiation efficiency of the heating element 2 and the water heating efficiency are further improved.

In the above construction, the upper surface 2a of the heating element 2 is
Although the convex portions 10 are formed on the upper surface 2a to form the unevenness, the upper surface 2a is formed by forming the concave portions on the contrary.
You may provide unevenness in a. When forming the concave portion on the upper surface 2a, the concave portion vertically penetrates the through hole 13 as shown in FIG.
It is preferable that As described above, since the heating element 2 is simply placed on the inner surface 4a of the bottom portion without being fixed thereto, water can penetrate between the heating element 2 and the bottom portion 4 through the through hole 13. The heat effect on the bottom portion 4 can be reduced by the infiltrated water.

Further, in the above embodiment, the space V is formed by forming the recess on the lower surface 2b of the heating element 2 or the bottom inner surface 4a of the container body 1, but the recess may be formed on both. Even when both the lower surface 2b of the heating element 2 and the bottom inner surface 4a of the container body 1 are formed to be substantially flat, for example, the lower surface 2b of the heating element 2 has a predetermined height from the bottom inner surface 4a of the container body 1. The space V is formed between the heating element 2 and the bottom part 4 of the container body 1 by separating the heating element 2 from the inner surface 4a of the bottom part so that the heating element 2 is housed in the container body 1 so as to be located above. May be.

Further, in addition to the structure in which water enters the space V through the gap between the peripheral surface of the heating element 2 and the inner peripheral surface of the container body 1, for example, as shown in FIG. A through hole 14 communicating with V may be formed so that a liquid such as water enters the space V. The shape of the through hole 14 may be, for example, a circular shape, an elliptical shape, a rectangular shape, or an elongated hole, and the size of the hole is about 1 to 5 mm in the case of a circular shape. The total area of the holes is approximately 1/3 of the upper surface 2a of the heating element 2.
The following is good.

In the above embodiment, the heating element 2 is placed on the bottom inner surface 4a without being fixed. However, even if the heating element 2 is fixed to the container body 1, for example, the bottom inner surface 4a,
By providing unevenness on the upper surface 2a of the heating element 2, it is possible to improve the heat radiation efficiency as compared with the conventional flat plate-shaped one.
As a result, damage to the bottom portion 4 due to heat can be suppressed.

In addition, the shapes of the heating element 2 and the container body 1 can be changed as appropriate. For example, the container body 1 may have a rectangular tube shape such as a quadrangle or a hexagon other than the cylindrical shape.

[0033]

As described above, since the upper surface of the heating element is provided with unevenness to increase the surface area of the upper surface as compared with the conventional case, the heat radiation efficiency of the heating element is improved during cooking, and thus the heating element Excessive heating is suppressed and damage to the container body due to heat can be suppressed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an induction heating cooking container according to an embodiment of the present invention.

FIG. 2 is a sectional view showing an induction heating cooking container according to another embodiment of the present invention.

FIG. 3 is a sectional view showing an induction heating cooking container according to another embodiment of the present invention.

FIG. 4 is a sectional view showing a main part of an induction heating cooking container according to another embodiment of the present invention.

[Explanation of symbols]

1 ... Container body, 2 ... Heating element, 2a ... Upper surface, 2b ... Lower surface,
3 ... Body, 4 ... Bottom, 4a ... Bottom inner surface, 6 ... Rib, 9 ...
Protrusions (regulating means), 10 ... convex parts, 11, 12 ... concave parts, 1
3, 14 ... Through hole, 20 ... Seal lid (lid), V ... Space portion, W ... Dried food (content)

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3K051 AB05 AC34 AD03 AD15 AD34                       BD21 CD17 CD44                 4B055 AA09 BA02 BA22 CA02 CA71                       CB03 CB07 CB17 DA02 DB14                       FA16 FB01 FC06

Claims (6)

[Claims] 1. A container for induction heating cooking, comprising: a bottomed cylindrical container body (1) made of a non-conductive material; and a heating element (2) that generates heat by electromagnetic induction, wherein the heating element (2) is A container for induction heating cooking, wherein the container is provided in a container body (1), and an unevenness is provided on an upper surface (2a) of the heating element (2). 2. A container for induction cooking according to claim 1, wherein a space (V) is provided between the heating element (2) and the bottom (4) of the container body (1). 3. A liquid such as water contained in the container body (1) is configured to be able to enter the space (V).
The induction heating cooking container described. 4. The heating element (2) is placed on the bottom inner surface (4a) of the container body (1), and the bottom inner surface (4a) of the container body (1) and the bottom surface (2b) of the heating element (2). The container for induction cooking according to claim 1, wherein at least one of them has a recess (11, 12). 5. The heating element (2) is placed on the bottom inner surface (4a) of the container body (1), and the heating element (2) is formed with through holes (13, 14) penetrating vertically. The container for induction heating cooking according to claim 1. 6. The induction heating according to claim 1, wherein a magnetic metal material having a Curie temperature lower than the melting point of the container body (1) plus 70 ° C. is used as a constituent material of the heating element (2). Cooking container.